You should see how much the one for the newer 177bhp 320d is, it's nearer £800, although that was when there were no remaps available for that model.
Yes, very impressed. Results from Awesome RR day when compared to a Superchipped 163bhp 320d (so, same engine but different dyno/different day) showed more gains lower down and a slightly higher top end, with the same mid-range - from memory.
DIP switches for different settings - mine is on full whack with no issues. There was practically no smoke when I first fitted it - 30k and I can make it smoke, but the air filter is probably clogged to ****.
Steinbauer offered me a higher flow program if I sent the box back to them to be reflashed.
Their direct support (you're supposed to go through distributors) fell away a bit when a guy called Matt left, but like I say, you shouldn't deal with them directly, your distributor should.
I know MikeP ran them for a while before Revo did maps for diesels and was very impressed when I spoke with him.
Connects to the accelrator pedal and injector loom on mine - I had some "fun" finding the correct wire at the pedal, but the injector end just plugs into the injector loom. Takes me 5 mins to remove the box and push the loom out of sight...